Mach Number Calculator
Calculate Mach number from airspeed and altitude, or calculate the airspeed for a given Mach number at a specific altitude.
Mach Number Results
Enter valid parameters to see results
About Mach Number
The Mach number (M) is the ratio of an object's speed to the local speed of sound. It is named after Austrian physicist Ernst Mach.
The speed of sound varies with altitude due to changes in air temperature and density. At sea level on a standard day, the speed of sound is approximately 343 m/s (1,235 km/h).
Flight regimes based on Mach number:
- Subsonic: M < 0.8
- Transonic: 0.8 ≤ M < 1.0
- Supersonic: 1.0 ≤ M < 3.0
- High Supersonic: 3.0 ≤ M < 5.0
- Hypersonic: 5.0 ≤ M < 10.0
- High Hypersonic: M ≥ 10.0
This calculator uses the International Standard Atmosphere (ISA) model to determine local air properties at the specified altitude.